WIP building wasm binding

.gitignore

@@ -111,6 +111,7 @@ coverage/
 /packages/realm/binding/build/
 /packages/realm/binding/android/build/
 /packages/realm/binding/node/build/
+/packages/realm/binding/wasm/build/
 /packages/realm/prebuilds/
 /packages/realm/binding/android/src/main/java/io/realm/react/Version.java
 /packages/realm/binding/android/src/main/jniLibs/

contrib/building.md

@@ -320,6 +320,28 @@ npm install path/to/realm-js/packages/realm
 > [!TIP]
 > To run any of the `"scripts"` commands from one of the `package.json` files directly from the root, use the `"name"` value from the target `package.json` as such: `npm run <command name> --workspace <package.json name>`.
 
+### Building for WASM (Browsers)
+
+Follow the steps to install the Emscripten SDK (emsdk) on https://emscripten.org/docs/getting_started/downloads.html.
+
+1. Clone the repository and enter the directory
+   ```
+   git clone https://github.com/emscripten-core/emsdk.git
+   cd emsdk
+   ```
+2. Pull, install and activate the latest version
+   ```
+   git pull
+   ./emsdk install latest
+   ./emsdk activate latest
+   ```
+3. Follow the instructions to setup environment variables for your shell (ex add this to your `~/.zshenv`)
+   ```bash
+   # Emscripten SDK
+   export EMSDK_QUIET=1
+   source "$HOME/<insert EMSDK sub-directory>/emsdk_env.sh"
+   ```
+
 ### Cleaning up build files
 
 If you need to clean up build files and other untracked files (except for `node_modules` directories), run the following command from the root directory:

integration-tests/tests/src/typings.d.ts

@@ -107,6 +107,10 @@ type KnownEnvironment = {
    * React native specific variable injected by the runner, to signal if the tests are ran by the legacy chrome debugger (i.e. in a browser).
    * @deprecated Since we no longer support the legacy chrome debugger. */
   chromeDebugging?: true;
+  /**
+   * Browser specific variable injected by the runner, to signal if we're running inside a Browser with WebAssembly.
+   */
+  browser?: true;
 };
 
 type Environment = KnownEnvironment & Record<string, unknown>;